43 CFR §3481.4-4

1. (a)If you (the lessee/operator) want BLM to consider your lease or LMU to be producing, the aggregate of all temporary interruptions in coal severance from your lease or LMU must not exceed 1 year in the 5-consecutive-year period immediately preceding the date of BLM's determination of lessee qualifications under § 3472.1-2 of this chapter.
2. (b)BLM will not count toward the aggregate interruption limit described in paragraph (a) of this section:
   1. (1)Any interruption in coal severance that is 14 days or less in duration;
   2. (2)Any suspension granted under § 3483.3 of this part; and
   3. (3)Any BLM-approved suspension of the requirements of § 3472.1-2(e)(1) of this part for reasons of strikes, the elements, or casualties not attributable to the operator/lessee before diligent development is achieved.